POS1103 BIMEKIZUMAB MAINTAINED IMPROVEMENTS IN EFFICACY ENDPOINTS AND HAD A CONSISTENT SAFETY PROFILE THROUGH 52 WEEKS IN PATIENTS WITH NON-RADIOGRAPHIC AND RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS: RESULTS FROM TWO PARALLEL PHASE 3 STUDIES
Authors: X. Baraliakos, A. Deodhar, D. Van der Heijde, M. Magrey, W. P. Maksymowych, T. Tomita, H. Xu, M. Oortgiesen, U. Massow, C. Fleurinck, A. Ellis, T. Vaux, J. Smith, A. Marten, L. S. Gensler
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Bimekizumab (BKZ), a monoclonal IgG1 antibody that selectively inhibits interleukin (IL)-17F in addition to IL-17A, met all primary/secondary endpoints at Week (Wk) 16 in patients (pts) with active non-radiographic axial spondyloarthritis (nr-axSpA) and radiographic axSpA (r-axSpA; i.e., ankylosing spondylitis), in the parallel phase 3 BE MOBILE 1 and 2 studies, respectively.<sup>[1,2]</sup> <h3>Objectives</h3> To assess efficacy and safety of BKZ in these pts up to Wk 52. <h3>Methods</h3> BE MOBILE 1 (NCT03928704) and 2 (NCT03928743) both involved a 16-wk placebo (PBO)-controlled and 36-wk maintenance period.<sup>[1,2]</sup> Pts were randomised to subcutaneous BKZ 160 mg Q4W (BKZ) or to PBO then BKZ from Wk 16 (PBO/BKZ). <h3>Results</h3> 220/254 (86.6%) randomised pts with nr-axSpA and 298/332 (89.8%) with r-axSpA completed Wk 52. Efficacy was sustained to Wk 52 in both studies (<b>Table 1</b>). ASAS40 responses in BKZ-randomised pts increased from Wk 16 (nr-axSpA: 47.7%; r-axSpA: 44.8%; non-responder imputation [NRI]) to Wk 52 (60.9%; 58.4%; NRI) with high levels of efficacy across TNFi-naïve and TNFi-IR populations (<b>Table 1</b>). At Wk 52, ASDAS &lt;2.1 was achieved by 61.6% and 57.1%, and ASDAS &lt;1.3 by 25.2% and 23.4%, of BKZ-randomised pts with nr-axSpA and r-axSpA, respectively (<b>Figure 1</b>). Wk 16 reductions from baseline in objective signs of inflammation (MRI, hs-CRP), and improvements in function (BASFI) and ASQoL, were maintained through 52 wks. Efficacy at Wk 52 was similar in PBO/BKZ-treated and BKZ-randomised pts (<b>Table 1</b>). At Wk 52, 75.0% (183/244) of pts with nr-axSpA and 75.5% (249/330) of pts with r-axSpA had ≥1 treatment-emergent adverse event (TEAE) on BKZ; the most frequent (% pts) TEAEs by preferred term (MedDRA v19.0) were nasopharyngitis (nr-axSpa: 12.3%; r-axSpA 9.1%) and upper respiratory tract infection (9.4%; 6.4%); few COVID-19 infections were reported (7.0%; 2.1%). Incidence (pts/100 pt years) of serious TEAEs were low (4.4; 7.1); no major adverse cardiovascular events, active tuberculosis cases, serious COVID-19 infections, or deaths were reported. Most incidences of fungal infection (19.6; 14.9; none serious or systemic) were <i>Candida</i> (12.8; 8.3) and mild to moderate; two pts in both studies discontinued the study due to <i>Candida</i> infections. Incidence of IBD (1.0; 1.0) and uveitis (1.5; 2.4) were low. <h3>Conclusion</h3> Across the axSpA spectrum, BKZ resulted in sustained efficacy to Wk 52. No new safety signals were observed, consistent with the Wk 24 safety profile.<sup>[1,2]</sup> <h3>References</h3> [1]Deodhar A. Ann Rheum Dis 2022;81:772–3; 2. [2]van der Heijde D. Ann Rheum Dis 2022;81:12–3. <h3>Acknowledgements</h3> This study was funded by UCB Pharma. Medical writing support was provided by Costello Medical, funded by UCB Pharma. <h3>Disclosure of Interests</h3> Xenofon Baraliakos Speakers bureau: AbbVie, BMS, Chugai, Eli Lilly, Galapagos, Gilead, MSD, Novartis, Pfizer and UCB Pharma, Paid instructor for: AbbVie, BMS, Chugai, Eli Lilly, Galapagos, Gilead, MSD, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, BMS, Chugai, Eli Lilly, Galapagos, Gilead, MSD, Novartis, Pfizer and UCB Pharma, Atul Deodhar Speakers bureau: Janssen, Novartis and Pfizer, Consultant of: AbbVie, Amgen, Aurinia, BMS, Eli Lilly, Janssen, MoonLake, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie, BMS, Celgene, Eli Lilly, MoonLake, Novartis, Pfizer and UCB Pharma, Désirée van der Heijde Consultant of: AbbVie, Bayer, BMS, Cyxone, Eisai, Galapagos, Gilead, GSK, Janssen, Eli Lilly, Novartis, Pfizer and UCB Pharma, Employee of: Director of Imaging Rheumatology BV, Marina Magrey Consultant of: AbbVie, Eli Lilly, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie and UCB Pharma, Walter P Maksymowych Consultant of: AbbVie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie and Pfizer; educational grants from AbbVie, Janssen, Novartis and Pfizer, Employee of: Chief Medical Officer for CARE ARTHRITIS, Tetsuya Tomita Speakers bureau: AbbVie, Astellas, BMS, Eisai, Eli Lilly, Janssen, Kyowa Kirin, Mitsubishi-Tanabe, Novartis and Pfizer, Consultant of: AbbVie, Eli Lilly, Gilead, Novartis and Pfizer, Huji Xu Speakers bureau: AbbVie, Janssen, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, Beigene, BioMap, IASO, Pfizer and UCB Pharma, Employee of: Clinical investigator for Peking-Tsinghua Center for Life Sciences, Marga Oortgiesen Shareholder of: UCB Pharma, Employee of: UCB Pharma, Ute Massow Employee of: UCB Pharma, Carmen Fleurinck Employee of: UCB Pharma, Alicia Ellis Employee of: UCB Pharma, Thomas Vaux Employee of: UCB Pharma, julie smith Employee of: UCB Pharma, Alexander Marten Employee of: UCB Pharma, Lianne S. Gensler Consultant of: AbbVie, Acelyrin, Eli Lilly, Fresenius Kabi, Janssen, Novartis, Pfizer and UCB Pharma, Grant/research support from: Novartis and UCB Pharma paid to institution.